Clutch for a two-speed propeller drive



July 27, 1954 J. s. HASBROUCK CLUTCH FOR A Two-SPEED PROPELLER DRIVE 5 Sheets-Sheet l Original Filed Sept. 21, 1946 ATTORNEY July 27, 1954 J. s. HAsBRoucK CLUTCH FOR TWO-SPEED PROPELLER vDRIVE 5 Sheets-$heet 2 Original Filed Sept. 2l, 1946 .IulIIllllI July 27, 1954 J, s. HAsBRoucK CLUTCH FOR A Two-SPEED PROPELLER DRIVE Original Filed Sept. 2l, 1946 INVEN-roR LIIHSBSPUUL'K,

AT TO R N E July 27, 1954 J. s. HAsBRoucK CLUTCH FOR A Two-SPEED PROPELLER DRIVE original Filed sept. 21, 1946 5 Sheets..sheet 4 lNvENToR g701mgglmmm July 27, 1954 J. S. HASBROUCK CLUTCH FOR A TWO'SPEED PROPELLER DRIVE Original Filed Sept. 21, 1946 5 Sheets-Sheet 5 www ATTORNEY Patented July 27, 1954 VCLUTCHFORFA TWO-SPEED PROPELLER DRIVE Continuation of application Serial No. 698,461, September" 2,1, 1946. This application June 15, 1950; Serial No. 168,327

r10 Claims.

invention :relates nto o. aircraft propeller drives `and particularly 'ftoz aitwo-speed transmisllesion fbetWeemam engine crankshaft and fits .pro- -fpellerti shaft, Van-d3means. :for changing the speed `=Lrnatiozcof transmission. "Thisfapplicationis a con- =f-.tinuation" of In yf-rzopendinge.V application..SerialA No. i'f69.8;46l;iiled September. 21, .1946;:now abandoned.. fA'prim'aric obiectfof'ftherinventioniis yto' provide .Qn'ov'el andfimproved.1 meansfor effecting changes sin .thevsp'eed ratior between anfr aircraft engine r-rzrankshaft and the propeller shaft driven thereby.

.Anotheri"emersi-,Foirl importancet is Eto-1 provide i Van izimprovedtwoespeed;reduction gear including a type of clutch which allows shifting from ione espeedtdthe othelorvithontfcornpletely disengaging .the engine fronr=the11propellen.or pausing in' a ,r ineutralf'or central: position awhile Vvsynchronizing .ithe' speeds-ofrltheimembers; 7whereby changes in 1f-the.speedrratidbflltransmissionbetween an engine :"cran'kshaft and a2propeller:.driventhereby.may be efeifectedfrapidiy,fpositively;fand dependablywith r1 minimums lessifs-power.

v4flariousfother? 'obiects'r-"and. advantages' willr be aapparentfas; ithenatureenf therinvention ri5. more ffu'lly disclosed fin Flan. illustrative embodiment "which isenowfeonsideredtobe a Apreferred.form @of wthe invention.

In certain-'.-typ'es .of fxnderner airplanes '.having highrmaximurrsfspeedstand 1relatively heavy-swing 1 ."loadings, itrthasrbeen ifoundid'esirable :to i provide ffmeans' foriizhanginglthespeednatioifbetween the -enginerand .iter-propeller. 1:1 Forfexamplef in` some b':installatinnsiiimnaybefouncb'desirable. to` operf a'tecthepropelleriatLaiyeryzhigharotatienal.speed `erfand#'with thefbl-ades: adjusted 'forz arelatively low 1,

f pitch anglerduringrizakeoff' 'in'zforderfto '.:d'evelop itheinecessaryntractiye'ithrust with:fthe-enginey opertnguY affmaximnm '1 power i vand' While the `air- .':plane--isftraareling'. at` relatively' slow speeds. As :the-,.speedf of theairplaneA increases# it :is desirable ItofoperatetheA fplopel'leri at a' -slower speed rela i. Ltiveto.- engine rspeed-,iwith..-the blades' adjusted for y,1-` higher -pitcheangle sin othery installations, yit '.mayHbe desirable.` .to..operatethe: propeller at` a f. lower. speed .relating toengine speed. during takeoff...than.inf cruising, .While in .stiILothercases .various .other reasons. exist-.for utilizing alter- .nativelyusable change speed gear'propeller` drives fof the .type referred to.

.An'e'fficienttwoespeied' reduction drive for situl ations offthe/above type isdis'closedin `my co pending application. Serial No. 568,108,` filed 4"Decennber 14;'1944;now"Patent No;` 2.444227, is-

suedA June 29,.1948 in which. a slidable 'clutch Imember is actuated'hyldrauli'cally 'toselectively engage either one `of proximately equal.

The present inventionI is arno'dioationof the change speed transmission:disclosed'inlmy application referred to above and employs a two-speed jackshaft'type propeller: drive'including highv and low speed gears, a noir-free Wheelingmechanism v associated with the high speed gear, and-a. jaw type shiftingl member fordrivingly connecting the engine crankshaft to'theprop`eller "shaft through either the high or lowspeed' gear. In charging from low to high speed gear connection, it is 4desirableto4 prevent the propeller'from being free-to rotateindependently'of the engine. It is, therefore,` r aiprincipal vobjeetof lthe invention to providev a *clutchA actingv when shifting from low to'highl gear Ato momentarily' drive `the -engine and'its' drivingr lconnections 'from 'the-propeller until -thevdriving connectionis complete.

The novel features characteristicfof-"this yin- -vention are set forth' more in'detail-in thezclaims lappended hereto, but the nature and scope vof the invention will be better understood vbyre- Vferring tothe following description,-taken in conneetion withthe accompanying drawings forming a part rthereof,-in which a specific andpreferred embodiment has beencset4 forth indetail-forppurposes of illustration.

In the drawings: "Fig lis a longitudinal 4sectional view of, aspeed changing mechanism embodying the present in- Y lven'tion, the section beingtaken substantially on i .the planes, of brokenline I-.-l, of. Fig. 2;

l Fig..2 is a transverse sectional viewrtakenon the. plane of line 2--2 =ofvFig. 1 and-on an enlarged sca-le;

-F'igp' 3 f is a; transversesectional- View :taken on the` planek of vline 3-4-3 zoffFigfl; showingr'part ofthe fshiftingrrnechanism;

2 Fig.V iis a fragmentary sectional viewsirnilar to Fig. 3 butwithitherparts in different' relative positions;

" centrally through Lthenranually'operatedshifting valve for hydraulically effecting the speed changes in the driving connections for the propeller;

Fig. 8 is a cross-section taken on the plane of line 3 8 of Fig. '7;

Figs. 9, and 11 are generally similar sectional views showing parts of the gear .shifting mechanism in successively different operative positions; and

Fig. 12 is a detail cross-sectional View of a spring construction normally holding a roller clutch in its disengaged position.

In the following description certain speciiic terms are used for convenience in referring to the various constructional details of the illustrated form of the invention. These terms, however, are to be interpreted broadly and limited only as the state of the art requires.

In the drawings, Fig. 1 shows a small part only of an engine crankcase IB and the forward end only of the engine crankshaft l2 which is rotatably mounted in a front bearing i3 formed in the crankcase lil. Co-axial with the crankshaft i2 and extending within a portion thereof is the propeller shaft lll having a propeller l5 (shown diagrammatically only) secured to its forward end. The propeller shaft i4 is supported within one or more anti-friction bearings l5 suitably mounted within a frame or housing il which may be bolted to the forward face of the crankcase lll and may enclose the speed change mechanism presently to be fully described. The propeller shaft lll is also supported by having its engine or trailing end extended to enter the forward end of the crankshaft l2, suitable bearings i8 and I9 being provided therein to permit relative rotation of the two shafts i2 and i4. Mounted on splines formed on the forward end of the crankshaft l2 is .a driving member in the form of a thin sleeve 2l having internal longitudinally extending splines 22 adjacent its rear end engaging the splines 2D on the crankshaft.

The sleeve 2l has external splines 23 adjacent its forward end, .and these external splines 23 engage corresponding internal splines 26 on the rear end of a ring gear member 24. This ring gear member is supported by a collar 25 formed thereon rotatably engaging the propeller shaft Ul forward of the crankshaft I2. Accordingly, it will be seen that the ring gear member 24 is supported coaxially of the crankshaft l2 and i propeller shaft le by the sleeve 2l engaging internal splines on the member 2i, and by the collar 25 rotatably supported by an intermediate cylindrical portion of the propeller shaft M.

On the propeller shaft lll at an intermediate portion thereof is a large driven gear 21 splined at 28 thereon and having its teeth meshing with the teeth of a plurality of pinions 29 on the forward portion of short intermediate shafts 30 arranged in a circular series concentric about the propeller shaft It .and rotatably mounted upon parallel axes within suitable bearings 3| provided therefor in the frame or housing il.

As shown in Fig. 1, each of the pinion shafts 3Q is provided with three spaced bearings 3| in alignment formed in the frame Il, the driving pinions 2S meshing with the gear 2l on the propeller shaft ifi being disposed between the forward and intermediate bearings. Pinions 32 and which are of different diameters and having different tooth numbers for driving the shafts 3i? at either of two speeds, are disposed between the intermediate and rear bearings 3l.

Pinions 32 and 33 are positioned adjacent each other on shaft Sli and are continuously in mesh with the intermediate ring gears 34 vand 35, respectively. As shown in Fig. 1, gear 55 is rotatably supported Concentrically of the crankshaft l2 on an annular flange integral with an annular member 3! keyed or splined to the ring member 24. Gear 34 is rotatably mounted in `a like manner on a ring 38 suitably splined to the front end of ring member 26. For purposes presently to be described, the member 38 is made in two companion members suitably secured together.

To operatively connect one of the gears 3ft or 35 drivingly to the crankshaft l2, an axially slidable annular member 39 is provided having splines on its inner annulus and radial clutch teeth on opposite sides adjacent its outer periphery. The splines formed on the inner annulus of shifting member 3Q are at all times loosely engaged with the elongated splines lil on the ring member Z4 so that member 3e may slide easily thereon. The radial clutch teeth @il adjacent the outer periphery of shifting member 39 on opposite sides mesh selectively with corresponding clutch teeth on a side surface at the inner periphery of one or the other of the intermediate ring gears 34 or $5, depending upon the operative position to which the shifting member 39 has been moved. With the shifting member 39 in one 0f its operative positions, a speed reduction is effective between the crankshaft l2 and propeller shaft lil through gears 3d and 32, and when the shifting member 39 has been moved axially to its other operative position, another reduction ratio is obtained through gears 35 and 33.

Movement of the shifting member it in either direction is effected hydraulically in the illustrated embodiment of the invention, for example by admission of fluid under pressure to one end or the other of one or more cylinders 42 shown in Fig. 2 within which pistons i3 are reciprocable. Each piston i3 is provided at its intermediate portion with a plurality of rack teeth dill, each rack meshing with a small spur gear 55. Each of the small spur gears t5 is mounted adjacent its piston on a short rotatable shaft te supported within a portion of the housing Il. On each of these shafts t5, at the inner end thereof, is provided an eccentric or crankpin il, which eccentrics engage at their free ends within a peripheral groove formed in an annular operating member or ring lili. The operating member 48 has teeth or splines 49 formed in a ring member 5l secured concentrically to the member 48 engaging corresponding splines on the ring member 24, permitting said operating ring li to slide longitudinally on ring member lll also cau.,- ing said operating ring Il@ to be rotated with the ring member 24, sleeve 2i and crankshaft l2.

Each of the crankpins ill is surrounded by a bearing member or shoe 50 directly engaging the side Walls of the groove in the operating ring ./i8. In one position of the pistons 43, the operating ring 48 is in one extreme position, and in the opposite position of the pistons the cra-nkpins il have been rotated slightly more than i559" and have moved the operating ring i8 to its opposite extreme position. Fluid under pressure is simultaneously admitted to corresponding ends of the cylinders di, within which the pistons i3 operate, through appropriate conduits 52 and (Fig. 2) from a manually controlled valve 5f, (Figs. 7 and 8) as hereinafter more fully del` scribed.

Operation of shifting the member 39 to change throughthe` operating 'member B-andltluetrnem- :aber l. The-.- sleevesmf::surround"rods .iihaw opposite, -vfaces: of. the-1Eshiftingitcmemberzr3.9. .:-=.As '.-slfiovfv'n in'ffFigs: 1 .9,1 lgiand. .-ll, the.: innen: portion w .'.ofazoneafseries nf 1 cup members. E@ bears: against .zthegends :o f. z helical springsn A56" surrounding .the :sleeves EB-:fandzzthefsopposite'series of clip-niem-y :bers: .62 :bears-against 'shorter helical` springsy 66, rtheioppositewendsof Which engage againstfianges xonazenlarged;portionsfof the rodsfta [Between eachfpair. ofcup rnembersfZ- and Se: is a spacing Washer `58-onffthe+rods-itil supportingrthe- -cup members 62-1 and 4. They rods are v.extended .toward the -left beyond their flanges/.and enter .-.suitable "openings for-med `in :onewof Ythe companion members'formng the ring: member-38- The :rst eiect of movement to the Ileftoi #operating ring f'and compression of the" helical .springs 565110 change :the speed ratio y'from low --to1high is :to force the extensionsofrods-:63 further into their-,openings .fina-gate ring 38. f,-Entry,1however, is .prevented-by a friction .clutch .memberf lli, the :openings Ain'iwhich'are `out of alignment ywitlrthose in the twocompanion parts of ring member 38. -Duringithis period' of ysynchronization the .rclutch-.membeiwSS `is .held in resilient .-engagementwitlr .low ratio gearf 35 byv `:springs-$55. v.This .makes it impossibletfor-.the :propeller v.tobecornef disengaged from the engine. It is held .ineonefdirectionfby the low fratio gear andinthe.-other-bythe roller clutch l. ..When `.rnotion'to the .left of the.-sleeves 58.and rods-50 yis* completed but before rods. -Sllha-ve. moved .to .the left or.. drivingk .Y positiony .the roller, .friction i .clutch member. 'wand the ring. member-N38 .with .the .intermediate gearA 34. vvill .-.be .rotated due -to .the rotation of. thepropeller. Y.Therotation-.of .the propellerl engages andholdstheriction .clutch .memberifl ini itsi.drivingpositionf. by .movelnentofthe .rollers i I 4to.thepositions kshown ,.in Fig.. 4. '..Immediately` followingthe ,completion of .motionto .the .left ...oft-he rods. 60. .and.their sleeves 58,. Whene .the openings in. members., A38 and? T10. are. in. alignment.. the..helic`al. springs. '.56 .compressed `by this. movement .expand and. movementor .tliebuter.cnp..members4 forcesihe yshifting. memberz -to theleft. Completion-oi Xthis movement ,ofshifting memberI .Bannion-.is a continuous movement.V positively .dri-ves.. .gear T34. Thisn'al position is .showninl Eig. .10.

Movement to the rightof the. rods.. and sleeves 58 from. the position .shovvnin Fig. 10 to '.tlrat shownin Fig.. ll whereuponthejaw teeth '..intermesnas shown inFig. .9,.Wl1en the. operating ring Mis moved-tothe right, nrstwithdrawsthe ...extensionsof rods 66 vfrom openings. Within the .clutch .member vl',.thusireeing .the intermediate egear 34. Also .theincreased `compression.of the .left hand series.A of .the shorter :helical vsprings it by this movement ot member-@8 tothe right forces .the shift -ringl 35,.,totne position-'shovvn-.in Eig. ll in which .the clutch teeth bean-against `thewends -.-.oi. i the .clutolrf-teethfon. gear 35. lliereaiteny .the clutoh member, 3 w when i its jaw. teeth.v interniesli with the'teeth.on :;gear 35; can ratchetauntil the speeds: of. lthe i two .rnembers arek the -J-saine, 1 after tfwlrich =:it. movesetogitsznal ordowaispeeddrivng 'firstrcompressesa;plurality `of helical;:springsl SL56 individually: .surrounding sleeves'.` 15 8: :extending I1511this controlring member 14 has itsange 'Miengaging a rol1 "l8,.;on. a piston operating member 1436i and serving, .finrthis :right ihand `position,`to hold the piston 52 Within cylinder 86. Movement of the operating ring 531130: .the leftandcorre- "sponding movement yof ftherods1 6i] movesthis ring' *M :to the leftiand permits movementiofithe piston 82 to `the left by spring 34housedfwithin ,itsgcylin'der' S6.

r-Withl thepistontZ in the positionrshovvnin Fig. 1', fluid under: pressure suppliedithrough-leon- :kd-uit '88 is cutf'offf-by thepiston' covering `the.port of this conduit. Conduit '96; however; leading :to :theengine speed regulating governor (not shown) is opento'fthedraini conduit-9i. The-'governor 130 which may be of the type as usedrwithvaircraft propellers and as shownin patent-xtofErleMartin 'fet al., Nd 2,365,204;granted'December19, 1944, is adjustedfora certainspeed` dependent upon" its :spring adjustment. `As* soon: as 'the control-'ring M .moves to the l'eft .\vl1en .shifting i from f low. `:to

high gearratioypistolr 82 .uncovers theiiuid sup- -ply port-@Band admits udto the governorto rincrease its; Speeder: spring. loading and increase .ftheengine speed -forsthefsame `throttle setting. Tnefroller type ffriction .clutch referredto above is shown in detail in Figs. 3 and 4. lDuring the shift from low to higlrspeed gear ratio' windmill- -ing of the: propeller f1' 5: duringflight rotates gear 34 .through-gears 21,42 SL and 32V and forces a series 445. for. rollersl l alongl :cam: paths Yformed in clutch member Alll. This :engagement of the rollers y-ll with an@ internal'. cylindrical. surface of gear 34 :.thenxfrictionally'drivesi :member InHi and `causes limited:angular movement between members 34 50... .and-'l0 andithenrelative movement betweennie1nbers '.153 and 3.8. The irelative angular-movement omernber1 lfand. member 38 Ybrings into alignz.ment:thefholesinmembers 38 and 'lil so that the frodsio .can move to their extreme leii'.-l'1andv po sitionaasshovvn in Fig: 1G. Inthis-final position .of rods-6l), .the shiftable member Se is in its driv- .iing.positionwrelativeto. gear 34. To assemble .the A,.imember lil relativi-tovv member r38 thev memberI 38 ismade inV two parts .as shownin 1 suitably retained in side by side relation.

`The. roller clutch member 7), when not driving or held insynchronizing position` bythe rodsil, is imaintainedin its overrunning or released position y.by compressed springsl Q2 bearing: against. and 65. Alioldingpairs` of opposed head-ed. members V911 f.. slightly separated. rlhe. semi-cylindrical heads .of oneof each-.pair1ofthese membersl Vbears against abutment surfacesformed in the two part ...member .38 vand .thesimilarly formedl heads .of fthe fopposite. member of `each `pair. bears .againstan abutment-surface.formed.in.member 1E). The ref. .cesses, .the -end surfacesfof which form the abutmentsffor .these headed 'members y:94. are Iso -defsigned-:thatfthe heads can lseparate adenitebut ;...fsmall amount only. The amount .of separationtlis sunicient to misalign the holes so that rod 60 cannot pass through.

When the headed members 94 are in the position shown in Fig. 4 with their springs 92 compressed and the headed members B as close together as possible the openings in members 38 and i6 are in axial alignment permitting movement to the left of bolts or rods Si) to their extreme or positive high gear driving position. When the rods 60 are moved toward their right hand position, to shift from high to low gear position, removal of the rods from their openings in member 'lll by partial movement of the rods releases the roller clutch by expansion of the springs 92 and relative rotative movement of the member 'lll and gearv Sli. In this low gear driving position the member 38, splined to member 24, rotates faster than gear 3G and thus retains the roller clutch in its released position.

In operation in shifting from low to high gear ratio, the throttle is momentarily released and the manual valve 513 moved by its handle to actuate pistons L23 to rotate crankpins 47 to their left hand position. Movement of sleeves 58 and rods 6B when completed moves abutment flange 'l5 on ring 'lli to permit valve 32 to move to the left. In this left hand position of valve 82 fluid under pressure is admitted from supply conduit 88 to the governor (not shown) to set the engine speed to a higher Pt. P. M.

When the shift is made from high to low gear ratio, the valve 82 is returned to the position shown in 1Eig. l permitting fluid from the governor to drain through conduit i The governor setting is then reset for the lower speed ratio.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from the spirit of the invention as dened by the following claims.

I claim:

1. In a shifting mechanism, a shiftable member movable between two positions, operating means, a resilient connection between said operating means and said shiftable member for holding said shiftable member in either of its two positions, said connection including a rod, a mechanism associated with the rod for indicating when said shiftable member can move in one direction from one position to the other, said resilient connection also including two washers mounted on said rod, a stop on said rod, a spring mounted on said rod between said stop and said shiftable member, a second spring mounted on said rod between the shiftable member and said operating means, said nrst named spring maintaining engagement of said shiftable member in an operating position until said indicating mechanism allows the shift to be made to the other operable position.

2. A shifting mechanism comprising, a shiftable member movable between two positions, operating means, a resilient connection between said operating means and said shiftable member for holding said shiftable member in either of its two positions, a mechanism associated with said resilient connection for indicating when said shiftable member can move in one direction from one position to the ot er, said resilient connection consisting of a rod whose movement is controlled by said mechanism having two stops thereon, two washers, mounted on said rod, one washer being engageable with one side of said shiftable member and the other washer being engageable with the other side of said shiftable member a spring mounted on said rod between one stop and one washer, a second spring mounted on said rod between the other washer and said operating means, said first named spring maintaining engagement of said shiftable member in an operating position until said indicating mechanism allows the shift to be made to the other operable position.

3. A shifting mechanism for a two-speed drive comprising a driven connection, two driving connections, an actuating device, a shiftable member movable thereby between two operative positions and having jaw teeth engageable with one or the other of the two driving connections in either operative positions, a resilient connection between said actuating device and shiftable member, one of said driving connections forming one element of a roller clutch, a second element of said roller clutch supported by said driven connection, said second element and driven connection having openings therein, said resilient connection having a part for controlling the movement of said shiftable member, biasing means by which said openings are normally resiliently maintained out of alignment, said openings being brought into alignment by action of said driving connection and the roller clutch, said misalignment maintaining said shiftable member inoperative by preventing said part from passing through said openings, said shiftable member being operable when the openings in said second element and said driven connection are in alignment since said part is thereby permitted to pass therethrough.

4. In a two-speed drive, an engine driven connection, two alternately engageable driving connections, an actuating device, a shiftable member movable thereby between two operative positions and having jaw teeth engageable with one or the other of the two said driving connections in either operative positions, resilient connections between said actuating device and shiftable member, one of said driving connections forming one element of a roller clutch, and a second element of said roller clutch supported by said driven connection, said second element and driven connection having openings therein, said resilient connections having a part for controlling the movement of said shiftable member, biasing means by which said openings are normally resiliently maintained out of alignment, and said openings being brought into alignment by action of said driven connection and the roller clutch, said misalignment maintaining said shiftable member inoperative by preventing said part from passing through said openings, said shiftable member being operable when the openings in said second element and said engine driven connection are in alignment since said part is thereby permitted to pass therethrough.

5. In combination, a propeller, an engine driven connection, two alternately engageable driving connections connected to said propeller, an actuating device, a shiftable member movable thereby between two operative positions and having jaw teeth engageable with one or the other of the two said driving connections to said propeller in either operative position, resilient connections between said actuating device and shiftable member, one of said driving connections forming one element of a roller clutch, a second element of said roller clutch supported by said engine driven connection, said second element and engine driven connection having openings therein, said resilient connections having a part for controlling the movement of said shiftabcd-739s ablefl member, biasing meansiby which saidflopen-1` ings .are normally `resilientlwmaintained-Loutilofi? alignment preventing completemovementtot saidf shiftable member to an operative positio'nby. pre-. venting said part from passing through said openings, said propeller rotating said'- roller clutch merrrberto align `Isaid 'openingsjand permit complete.-movement of said .shifting memberw since said part is thereby permitted to',r pass.`

therethrough.`

6. A shifting mechanism for a .two-speed. Cdr'ive comprising,v a ,driven lconnection, alternatelylen-,- gageable driving connections, 'an yactuating device, a shiftable member movable thereby between two operativefpositionsandfhaving jaw teeth engageable with one ofthe two alternately engagea-ble vdriving connections neither ioperative position, resilient connections between said actuating device and shiftable member, one of said driving connections forming one element of a roller clutch, a two-part member having a series of aligned openings therein mounted on said driven connection, an annular member mounted coaxially with said two-part member and having a series of openings therein, said resilient connections having a part for controlling the movement of said shiftable member, resilient members disposed between said twopart member and said annular member normally maintaining said openings out of alignment, a r

second roller clutch element on said annular member, said openings being out of alignment when said clutch is disengaged thereby preventing the movement of said shiftable member to an operative position by preventing said part from passing through said openings, and said openings being aligned by engagement of said clutch and permitting movement of said shiftable member to be completed since said part is then permitted to pass therethrough.

7. A shifting mechanism for a two-speed drive comprising, an operating device, a shiftable member movable between two operative positions and having teeth on both sides thereof, means driven by said shiftable member having spaced sets of teeth, each set forming a driving connection with the cooperating teeth on said shiftable member in its operative position, a resilient connection between said operating device and shiftable member for holding the teeth of said shiftable member in engagement with the cooperating set of teeth on said means in its operative position until said shiftable member is ready to move directly to its other operative position, a synchromesh mechanism for indicating when said shiftable member is ready to move directly to its other operative position, said resilient connection comprising a spring for acting between said operating device and said synchro-mesh mechanism when said shiitable member is not ready to move directly to its other operative position and for acting between said operating device and said shiftable member when said shiftable member is ready to move directly to its other operative position and a second spring acting to hold said shiftable member in its operative position until said shiftable member is ready to move directly to its other operative position.

8. A shifting mechanism for a two-speed drive comprising, an operating device, a shiftable member movable between two operative positions and having teeth on both sides thereof, means driven by said shiftable member having spaced sets of teeth, each set forming a driving connection with the cooperatingv teeth on said shiftable member in its operative position, a ref'. operative position. until f-said shiftabl'e member-l is f` readyto move directly to-itsiotheroperative posi-- tion-fra :synchro-mesh? mechanism vfor indicating when/.said :shiftable' member-1 'isx read-yf to move di-l rectlyito -its-'other 'ioperativ'e position, Asaid f resilientlconnection comprisingfr a f rod "which l passes through :a hole in -said-shiftable memberyone end oifi'said rod coasting with said!synchro'-mesh'v mechanism; Y the other `'endfcoactingl withy saidv operating-udevicefla Istop on said f rod, a washery member on-zsa-idrod between said stop and said operating-device for engaging said shiftable mem'- -v brffa second:washermemberI onsaid iod for r`errl a spring around said rod between said rstnamed washer member and said operating device, a second stop on said rod and a second spring around said rod between said second washer member and second stop on said rod, said second spring maintaining engagement of said shiftable member in an operating position until said synchro-mesh mechanism is ready to allow said shiftable member to shift to its other operative position.

9. A shifting mechanism for a two-speed drive comprising, an operating device, a shiftable member movable between two operative positions, and having teeth on both sides thereof, means driven by said shiitable member having spaced sets of teeth, each set forming a driving connection with the cooperating teeth on said shiftable member in its operative position, a resilient connection between said operating device and shiftable member for holding the teeth of said shiftable member in engagement with the cooperating set of teeth on said means in an operative position until said shiftable member is ready to move directly to its other operative position, a synchromesh mechanism having openings therein which when aligned indicate when said shiftable member is ready to move directly to its other operative position, said resilient connection comprising a rod which passes through a hole in said shiftable member and is positioned so that it passes through the openings of the synchro-mesh mechanism when aligned, the other end of said rod coacting with said operating device, a stop on said rod, a washer member on said rod between said stop and said operating device for engaging said shiftable member, a second washer member on said rod for engaging the other side of said shiftable member, a spring around said rod between said rst-named washer member and said operating device, a second stop on said rod and a second spring around said rod between said second washer member and second stop on said rod, said second spring maintaining engagement of said shiftable member in an operating position until said synchro-mesh mechanism is ready to allow said shiftable member to shift to its other operative position.

10. A shifting mechanism for a two-speed drive comprising, a driven connection, two driving connections, an actuating device, a shiftable member movable thereby between two operative positions and having jaw teeth engageable with one or the other of the two driving connections in either operative position, a resilient connection between said actuating device and shiftable member, one of said driving connections forming one element of a roller clutch, a second element of said roller clutch supported by said driven connection, said second element and driven connection having openings therein, said resilient connection having a rod for controlling the movement of said shiftable member, said rod extending through a hole in said shiftable member, a stop on said rod, tWo Washers mounted on said rod, a spring on said rod between said stop and one of said washers, a second spring between the other of the two washers and the actuating member, biasing means by which said openings are normally resiliently maintained out of alignment, said openings being brought into alignment by action of said driving connection and the roller clutch, said misalignment maintaining said shiftable member inoperative by preventing said rod from passing through said openings when said rod is biased in that direction by said second spring, said shiftable member being operable when the openings in said second element and said driven connection are in alignment since said rod is thereby permitted to pass therethrough.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,175,014 Roger Mar. 14, 1916 1,177,133 Parker Mar. 28, 1916 2,318,328 Nallinger May 4, 1943 2,444,227 Hasbrouck June 29, 1948 2,512,103 Hoiman et al June 20, 1950 FOREIGN PATENTS i Number Country Date 67,083 Norway Nov. 15, 1943 

